LTE support for more carriers (complete list of supported carriers here)

Purchase movie tickets through Fandango with Siri (USA only)

iTunes Match subscribers can now download individual songs from iCloud

New button to reset the Advertising Identifier

9to5Mac is also reporting that the update includes Bluetooth keyboard compatibility for the Apple TV, which could be pretty handy. Open up iTunes or head to Settings > General > Software Update on your device to get the new version. Of course, if you plan on jailbreaking, you may want to hold off just in case the new version isn't supported in the next jailbreak.